The invention relates to an energy-absorbing device, particularly for rolling stock.
Energy-absorbing devices are used in vehicle technology for taking up kinetic energy, for example, upon a damaging impact caused by colliding with an obstruction. During such an occurrence, the energy is absorbed in a controlled manner by parts that are especially provided on the vehicle for such a purpose.
In order to introduce new safety features in rolling stock, for example, in the frontal area of a locomotive, deforming regions must be provided which, in view of the enormous mass of the train, are capable of absorbing high amounts of energy. In particular the engineer's cabin must be sufficiently protected during an impact. The space required for such a purpose, however, is severely limited at such a location so that ideally an existing construction should be used for installing an energy-absorbing device. The rigid parapet region in particular provides hollow-chamber profiles with varied profile cross sections and a high bending moment of inertia, which can only be used, however, if the dimensions of the energy-absorbing device can be adapted for installation. The energy-absorption device may also be used in aviation, for example, in helicopters, where it may be installed in the seat to protect the pilot if hard impact occurs.
Steel tubes which absorb the energy by folding, tapering or by means of a rolling bending are known and are described in current text books such as Lang, K., Manual for the Metal Forming Technology, (1975), Vol. 3, p. 211 ff and the Encyclopedia for Materials Technology, VDI Press (1991), p. 1858 ff. Further, French Published Patent Application 2 698 034 A1 and U.S. Pat. No. 4,829,979 disclose, for a similar purpose, tubes made of a fiber-reinforced plastic, which absorb energy by fiber/matrix breakages.
A comparison of the various materials as to their energy-absorbing property shows that plastics are far superior to metals. However, plastic materials have the disadvantage in practice that force-locking connections with other components can be made only with very significant expenditure, if at all.